自学英语新概念第二册第21课
语法：
被动语态：
一般现在时：am/is/are done
一般过去时：was/were done
现在进行时：am/is/are doing done
过去进行时：was/were doing done
现在完成时：have/has been done
过去完成时：had been done
情态动词被动：现在时
will/would be done
may/might be done
can/could be done
must be done
have to be done
过去时：
must have been done
can not have been done
may have been done
短语：
be mad at sb
for some reason
be determined to do sth
offer sb sth=offer sth to sb
a large sum of
come into use
#英语#
